Direct Cloning, Expression and Purification of Human Activated Thrombin in Prokaryotic System and CD Analysis Report of Produced Thrombin: Molecular Characterization of Recombinant Thrombin

Preparation of magnetic poly(ethylene glycol dimethacrylate-N-Methacryloyl-(L)-glutamic acid) particles for thrombin purification

In this study, magnetic poly(ethylene glycol dimethacrylate-N-methacryloyl-(L)-glutamic acid) (mPEGDMA-MAGA) particles were prepared by the dispersion polymerization in order to purify thrombin effectively. mPEGDMA-MAGA particles were synthesized by adding different ratios of magnetite (Fe₃O₄) to the medium in addition to the monomer phases EGDMA and MAGA. The characterization studies of mPEGDMA-MAGA particles were used by fourier transform infrared spectroscopy, zeta size measurement, scanning electron microscopy and electron spin resonance. mPEGDMA-MAGA particles were used in thrombin adsorption studies from aqueous thrombin solutions in both batch and magnetically stabilized fluidized bed (MSFB) system. Maximum adsorption capacity in pH 7.4 phosphate buffer solution is 964 IU/g polymer and 134 IU/g polymer in MSFB system and batch system, respectively. The developed magnetic affinity particles enabled the separation of thrombin from different patient serum samples in one step. It has also been observed that magnetic particles can be used repeatedly without significant reduction in adsorption capacity.

Purification and characterization of thrombin from camel plasma: interaction with camel tick salivary gland thrombin inhibitor

BACKGROUND

Thrombin is the most important enzyme in the hemostatic process by permitting rapid and localized coagulation in case of tissue damage. Camel thrombin is the natural and proper target enzyme for the previously purified camel tick salivary gland thrombin inhibitor.

RESULTS

In this study, the camel thrombin was purified homogenously in a single affinity chromatographic step on the heparin-agarose affinity column with a specific activity of 3242 NIH units/mg proteins. On SDS-PAGE, the purified camel thrombin contained two forms, 37 kDa α-thrombin and 28 kDa β-thrombin, and the camel prothrombin was visualized as 72 kDa. The camel thrombin Km value was found out as 60 µM of N-(p-Tosyl)-Gly-Pro-Arg-p-nitroanilide acetate and displayed its optimum activity at pH 8.3. The PMSF was the most potent inhibitor of camel thrombin. Camel tick salivary gland thrombin inhibitor has two binding sites on camel thrombin and inhibited it competitively with Ki value of 0.45 µM.

CONCLUSIONS

The purified camel thrombin was found to be more susceptible toward the camel tick salivary gland thrombin inhibitor than bovine thrombin.